In recent years, a projector (projection display apparatus) that projects images on a screen has been widely used in not only offices but also homes. The projector carries out display operation in such a manner that image light is generated by modulating light from a light source with use of a light valve (spatial modulation device) to project the resultant image light on a screen (for example, see PTLs 1 and 2). Recently, a palm-sixed ultracompact projector, a mobile phone with a built-in ultracompact projector, or any other similar apparatus has begun to become widespread.